Air-compressor.



(No Model.)

H. sTn'ATER.

AIB CUMPBESSDB.

Application fxled July 29, 1901.)

Patented Oct. 22, IQUI. i

.n .-1 mmunm JL ls ,evans co.. vnmuumo.. wAswsToN'. n. c.

"lA llllllllllll Patented O ct. 22, i901.

H. sTnATfn. AIR COMPRESSUR.

(Application led July 20, 1901.)

2 sheets-sheet 2.

(No Model.)

u if I||1 I CII M V W (Yi 1.7/0 /6 ,C i@ j UNITED STATES PATENT EEICE.

HERMAN STRATER, on BOSTON, MASSACHUSETTS.

AIR-COMPRESSOR.

SPECIFICATION forming; part of Letters Patent No. 684,955, dated October 22, 1901.

Application led July 20, 1901. Serial No. 693049. (No model.)

This invention relates to air-compressing apparatus ot' the hydraulic type, wherein a suitable liquid, usually water, is employed as the compressing agent, the air being compressed thereby in a suitable chamber provided with admission and discharge ports for the liquid, automatically operated by mechanism which through suitable valves opens and closes the ports at the proper time.

In another application filed by me March 16, 1901, Serial No. 51,563, I have shown and described novel air-compressing apparatus of the type above referred to, vthe valve-actuating mechanism including a hydraulic motor, and in order to provide for the quick and effective operation thereof I devised means for eiecting the admission of the compressing agent to the motor at substantially the pressure of the source of supply, while such compressing agent is admitted at a lower pressure to the compressing-chamber. By such construction and arrangement a regulation of the pressure of the agent in the chamber does not alter the pressure of such agent supplied to the motor, so that the latter can work under full pressure. In my said application the means for eiecting such difference of pressure is located wholly within the compressing-chamber, so that it is necessary to open the latter when a change in the pressure of the compressing agent entering such chamber is desired. As for some purposes it is quite desirable or even necessary to vary such pressure from time to time, the apparatus forming the subject-matter of my said application is somewhat inconvenient, and my present invention has for its object the production of an air-compressor of the type hereinbefore referred to, but provided with pressure-regulating means of novel construction and at all times under the instant control of the operator. The motor is operated under a constant pressure, substantially that of the source of supply of the compressing agent,

while the pressure of such agent employed in' shown in elevation, as is also the means exj ternal to the chamber for varying the pressure of such agent as admitted to the chamber. Fig. 2 is an enlarged vertical section taken through the cylinder of the hydraulic mechanism to more clearly illustrate the operation of such mechanism, the section being taken on the line .fr Fig. 3. Fig. 3 is an enlarged sectional vieur showing the main inlet-passage for the compressing liquid and the outlet passage for the motor-exhaust. Fig. 4 is adetail in elevation, on a smaller scale, of the cylinder of the hydraulic motor with the valve-ports thereof. Fig. 5 is a detached detail, in elevation, of the valve and valve-chest. Fig. 6 is a vertical longitudinal section, on the line w w', Fig. 7, of the pressure-regulating connection between the liquid-supply and the comprcssing-chamberand motor; and Fig. 7 is a transverse sectional view thereof on the line 002 x2, Fig. 6, looking toward the left.

Inasmuch as the hydraulic motor and the mechanism operated thereby for controlling the inlet and outlet of the compressing liquid to and from the compressing-chamber is subf stantially the same as shown in my said aplIco 2,) the conduit opening into a trap T, which communicates with the main waste-pipe (not shown) by an outlet 150.

An upright standard B, secured to the base and extending up into chamber A, has two conduits or passages therein, s and m, the lower end of the former (shown in full lines, Fig. 2) registering with a short passage s in an enlargement AX of the base, the upper tubular end B' of the standard B, which forms a continuation of the conduit s, being bent over in the upper part of chamber A and closed at its end by a suitable plug b'. An admission-port b2, having an annular valveseat b3, is made in the under side of the overhang B', directly above the discharge-port a. A strong bracket B10 is secured at its foot to the base and at its upper end is secured to the plug b', as shown in Fig. 2, the bracket serving to support the cylinder of the hydraulic motor, to be described. The conduit m (shown in dotted lines, Fig. 2) opens at its upper end into a chamber fm in the standard B and at its lower end registers with a passage m (see dotted lines, Fig. 2) in the part A of the base, the passages s' and m being arranged side by side and connected at their outer ends by short pipes s2 m2 with a head M. (See Fig. l.) The compressing liquid (usually water) is admitted to the chamber A through the admission-port b2, the inlet-conduit s being connected by passage s', through pressure-regulating means, to be described, with a water-supply, such as the city mains, the gradual accumulation of the water in the chamber compressing the air contained therein, the compressed air passing through an outlet a2 and nozzle a3 to a storage-receptacle or to the apparatus which is to utilize the compressed air,a check-valve a4 preventing return of the latter to the chamber. After compression of the air to the desired extent the admission-port is closed and the outlet-port a opened for discharging the liquid in the chamber, and a fresh charge of air enters the chamber through an inlet 61.5, Fig. l, controlled by a check-valve a0. Valves V V coperate with the admission and discharge ports, respectively, and said valves are secured to the end of a piston-rod c, which passes through stufling-boxes inthe heads of the lnotorcylinder C, the latter having ports 3 4c at opposite ends thereof, communicating at their other ends with a valve-chest C', shown as containing or forming the chamber m in the standard B, Fig. 3. In Fig. 4f the extension eX of the cylindercasting shows the ports or passages 3 and 4, andan exhaust-passage c' is shown having one end or port at 5 and the other at 6. (See also Fig. 3.) The extension 0X is secured to the valve-chest C by bolts 7, and the chamber mx contains the valve c3, (best shown in Fig. 5,) rigidly secured to an oscillating spindle c4, and having a recess ci therein to effect communication between the exhaust-port 5 and either cylinder-port 3 or 4, the valve-spindle c4 being extended through the extension cX and having a finger es adjustably secured to its outer end by a set-screw l0, Fig. 1. The valve actuator herein shown comprises a swinging arm 7L, loosely fulcrumed on the spindle o1 and having a weight I-I at its upper end, its forked lower end providing two branches h', having each a tappet h2, located on opposite sides of and alternately coperating with the finger es. The operation of this part of the apparatus is well known, the Weight H throwing the actuator, as soon as it passes dead-center, so that one of the tappcts h2 will hit the finger c8 a quick blow, to thereby turn the spindle c4 in one direction or the other, to thereby change the position of the motor-valve c3.

A float F, Fig. 1, in the chamberAimparts initial movement to the actuatorh in wellknown manner, the risc of liquid in the chamber acting through the float to swing the actuator from left to right, and the fall of the liquidlevel effects the swing of the actuator from right to left. The float is secured to an arm f, fulcrumed on a stud f, secured to a part of the cylinder extension eX, the arm having upturned branches f2, diverging from its fulcrum and shown in Fig. l as having rollsfsj in the path of movement of and at opposite sides of the actuator h, and, as shown, the

arm f forms a bent continuation of one of the branches f2. Fixed stops 25, secured to the base A', serve to limit the throw of the actuator-weight II.

ln the drawings the admission-port b2 is open and the valve V' is seated, closing discharge-port a, and at such time the port lof the cylinder will effect exhaust of the latter below the piston CX by the recess c5 in valve c3 to exhaust-passage c', and port 3 will be admitting liquid to the cylinder above the piston. Shifting of valve ci by the actuator h, when the latter moves into dotted-line position, Fig. l, connects the port 3 with the exhaust-port c and establishes direct communication between the port 4f and the supply of liquid, causing a quick and powerful upward movement of the piston CX, simultaneously opening discharge-port a and closing the admission-port b2.

As the ports 3 and 4E open directlyinto the chamber mx, the full pressure of the liquid is utilized to act upon the piston and maintain the valves V V'in desired position irrespective of the pressure within the compression-chamber A. A third conduit or passage s3 in the standard B communicates at its upper end with the end G of the exhaust-passage c', and at its lower end it opens into the trap T, the motor-exhaust being thus independent of and separate from the dischargepassage of the compression-chamber.

Vhile the pressure of the liquid which operates the motor is substantially constant, it will be manifest that it is very desirable to vary the pressure of the liquid in the chamber A, so that the air will be compressed to IOG IIC

therequired density, and this density4 will usually vary, according to the work to be performedbythecompressedair. SoIhave herein provided a very convenient, simple, and effective pressure-regulating device, operative at all times and instantly without any disturbance of the compressing apparatus or interference with its operation.

Referring to Figs. l, 6, and 7, I have shown such pressure-controlling means as forming a part of the device for connecting the hydraulic mechanism and the admission-port b2 with the common liquid-supply.

A coupling comprising a case or shell D has a through-passage d therein communicating at its inlet end with a nipple d', adapted to be connected with theliquid-supply, the other or outlet end communicating by a duct d2 (see dotted lines, Fig. 6) with the outer face of a head cl3, (shown as externally screwthreaded.) A second duct d4, Fig. 7, leads directly from the lower part of the case D to said head d3, so that when the head is butted against the head M, Fig. l, the outer ends of the ducts d2 and d4 will register, respectively, with the ends of the passages m2 s2, and the former will, by means of the through-passage cl, communicate directly with the source of liquid-supply. AcouplingmemberorringMX is screwed onto the head cl3 and connected rotatably with the head M in usual manner to tightly hold the faces of the heads close together without leakage. The through-passage d is shown as having a port dx, Figs. 6 and 7, which opens into the case D and is controlled by a puppet-valve d5, its stem d6 being guided in a recessed cap (t7, which closes the lower opening in the case, so that the valve d5 can move toward or from the port dx. The top of the case is provided with an interiorlythreaded hub d8, having an annular inturned iange dg, on which is seated a flexible diaphragm E, of stout rubber, thin metal, or other suitable material. A C-shaped yoke e loosely embraces the through-passage d, (see Fig. 7,) and the valve d5 is screwed into the lower end of the yoke, the upper end of the latter bearing against the lower face of the diaphragm and having an upturned threaded shank c extended through it. A nut e2, having a large base, is screwed upon the shank and tight-ly upon the top of the diaphragm, securely connecting the latter and the yoke and preventing leakage around the spindle, the nut being movable up and down in the recessed lower end of an upright nipple d10, which is screwed into the hub d8 and bears upon the diaphragm near its periphery, holding it liquid-tight upon the seat di. The nipple is interiorly threaded, as at e112, to receive a tubular shank du, depending from an annular head du, provided for convenience with a thumb-nut cll. A strong spiral spring S8 is inserted in the tubular shank between the top of the nut e2 and the under side of the head d, and by screwing the shank (Z13 into the nipple d10 the spring will be compressed to a greater or less extent. The liquid entering the coupling from the source of supply through the inlet d' passes along the through-passage d and thence, as has been described, to the motor to operate the valves V V against the pressure in the chamber A, andI am enabled to use a comparatively small yet powerfulr motor to operate such valves, the motor being actuated by the compressing liquid at full pressure. At the same time the liquid in the through-passage tends to pass into the case D through the port dx, provided the valve d5 is open, the spring S8 acting upon the upper side of the diaphragm, tending to open such valve, while the pressure of the liquid in the case acts upon the under side of the diaphragm E, tending to seat the valve and close the port dx. Now by regulatingthe pressure of the sprin g in accordance with the full pressure of the liquid from the source of supply and according to the working pressure desired in the compressing-chamber it will be manifest that the liquid which passes through the case D and out through the outlet d4 to the compressing-chamber will enter the latter at any desired pressure below the full pressure of the liquid as it is received from its source of supply. Should the diaphragm become ruptured, leakage through the nipple d10 can be prevented by simply screwing down the shank C113 until the head d14 is seated on the annular upper end of the nipple, and, if desired, a washer w of suitable material maybe placed upon the tubular shank, immediately below the head.

The structure herein shown and described is very effective in its operation, is powerful and rapid, and at the same time it is abso-` lutely controllable at any time from the eX- terior of the. compressing-chamber, so that the working pressure in the latter can be varied from time to time, as desired.

My invention is not restricted to the precise construction and arrangement herein shown, as various changes or modifications may be made without departing from the spirit and scope of my invention.

The valve actuating mechanism herein shown is not claimed, broadly, as the same is covered by claims in my pending application hereinbefore referred to.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is@

l. In an air compressor, a compressingchamber having admission and discharge ports for the compressing liquid, hydraulic mechanism, operated by such liquid, to automatically open and close said ports, and means to independently connect the hydraulic mechanism and the admission-port with a common liquid-supply, said means including a device operative from the exterior of the compressing-chamber to vary the pressure of the liquid entering the same irrespective of the liquid supplied to the hydraulic mechanism.

2. In an aircompressor, a compressing- IOO chamber having admission and discharge ports for the compressing liquid, hydraulic mechanism, operated by such liquid, to antomatically open and close said ports, a coupling located outside the chamber to independently connect the hydraulic mechanism and the admission-port with a common liquidsupply, and means within the coupling to vary the pressure of the liquid entering the chamber irrespective of the liquid supplied to the said hydraulic mechanism.

3. In an aircompressor, a compressingchamber having admission and discharge ports for the compressing liquid, hydraulic mechanism, operated by such liquid, to automatically open and close said ports, a coupling located outside of the chamber and having an inlet adapted to be connected with the liquid-supply, two outlets adapted to be operatively connected with the admission-port and the hydraulic mechanism, respectively, and pressure-regulating meansinterposed between t-he said coupling-inlet and the outlet thereof in connection with the admission-port of the chamber.

4. In an air-compressor, a compressingchamber having admission and discharge ports for the compressing liquid, hydraulic mechanism, operated by such liquid, to automatically open and close said ports, a coupling located outside of the chamber and having a through-passage adapted to connect the liquid-supply and the hydraulic mechanism, said passage having a port opening into the case of the coupling, an outlet for the case, adapted to be connected with the admissionport of the chamber, a valve for the port in the th ro ugh-passage, and means to exert a variable pressure on said valve, whereby the pressure of the liquid passing through said port to the chamber can be regulated at will.

5. In an air-compressor, a compressingchamber having admission and discharge ports for the compressing liquid, coperating valves,actuating mechanism therefor,includ ing a hydraulic motor operated by the compressing liquid, means located between the liquid-supply and the chamber, to admit the liquid to the latter at a pressure variable at esegesi;

will and to the motor at the pressure of the supply, and cont-rolling means for the motor, governed by the level of the liquid in the compressing-chamber.

6. In an air compressor, a compressingchamber having admission and discharge ports for the compressing liquid, coperating Valves,actuating mechanism therefor, including a hydraulic motor, separate supply-conduits communicating with the motor and the admission-port, a coupling exterior to the chamber, to connect said conduits with a common liquid-supply, and means carried by the coupling to at will vary the pressure of the liquid supplied to the admission-port conduit irrespective of the pressure in the motor-conduit.

7. In au air compressor, a compressingchamber having admission and discharge ports for the compressing liquid, coperating valves,actuating mechanism therefor, including a hydraulic motor, separate supply-conduits communicating with the motor and the admission -port, a coupling exterior to the chamber, having a through-passage provided with a port opening into the coupling-case and adapted to be connected at its ends with the liquid-supply and the motor-supply conduit, an outlet-port for the case, to be connected with the admission-port supply-conduit, a flexible diaphragm in the coupling, a valve connected therewith for the port in the through-passage, pressure of the liquid in the case acting upon one side of the diaphragm to seat the valve and close the said port, and adjustable means acting upon the opposite side of the diaphragm to open the port, whereby the pressure of the liquid passing through the coupling to the compressing-chamber can be reduced at will below the pressure of the liquid-supply.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HERMAN STRATER.

Witnesses:

JOHN C. EDWARDS, AUGUSTA E. DEAN. 

